Could a common heart drug stop diabetes-related heart failure?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria * Type 2 diabetes mellitus * On at least one oral hypoglycemic agent, or glucagon-like peptide analogue or insulin, for at least 6 months * EF \> 50% without diastolic dysfunction or EF \> 50% with grade 2 or more diastolic dysfunction, without prior diagnosis, or signs and symptoms, of heart failure * Minimal distance of \>450 meters on a 6-minute walk. If the subject is not able to walk 450 meters due to pain in hips and/or knees, and not fatigue or shortness of breath, then they will still qualify for the protocol. Exclusion Criteria * HbA1C\> 9 % at enrollment * prior diagnosis, or signs and symptoms, of heart failure; * Currently taking a loop diuretic * myocardial infarction within 6 months of Visit 2 * unstable angina within 6 months of Visit 2 * significant (\> moderate) valvular stenosis, hypertrophic, restrictive or obstructive cardiomyopathy, constrictive pericarditis, primary pulmonary hypertension, or biopsy proven active myocarditis * severe congenital heart diseases * sustained ventricular tachycardia or ventricular fibrillation within 14 days of screening * second or third degree heart block without a permanent cardiac pacemaker * stroke within 3 months of screening, or other evidence of significantly compromised CNS perfusion * ALT \>2 times the upper limit of normal * serum sodium of \< 125 mEq/dL or \> 160 mEq/dL * serum potassium of \< 3.5 mEq/dL or \> 5.9 mEq/dL * hemoglobin \< 9 gm/dl * eGFR \< 30 ml/min (at screening) * other acute or chronic medical conditions or laboratory abnormality which may increase the risks associated with study participation or may interfere with interpretation of the data * received an investigational drug within 1 month prior to dosing; * patients with an allergy to iodine * female subject who is pregnant or breastfeeding * in the opinion of the investigator, is unlikely to comply with the study protocol or is unsuitable for any reason